Many advantages to wood framing, including its cost

April 29, 2006

SENSIBLE HOME JAMES DULLEY Q. I am planning to build a new two-story house. I want it to look conventional and be energy efficient, but not cost a fortune. Is traditional wood framing construction an efficient option? A. There are many new super-efficient house construction methods available today. Some of these finished houses look conventional, while others look "super-efficient." With the utilization of some passive solar heating, some can be "net-zero," meaning they require no heating equipment. Although traditional wood-framing does not always produce the most efficient house, it has advantages. We have ample lumber in this country, and it is a renewable resource. The cost of building with wood is reasonable. It is not difficult to find contractors experienced with framed walls. In order to be more energy efficient and cost effective, discuss using a framing design that requires the least amount of lumber without sacrificing strength. Always consult your local building codes. By using less lumber (wall studs, headers, cripples, etc.) inside of the wall cavities, there is more room for continuous insulation. Using engineered lumber and trusses also conserves lumber. The first step is to design your house in two-foot increments and plan on using two-by-six wall studs spaced on 24-inch centers. Houses often use two-by-four studs on 16-inch centers. By sizing your house and rooms accordingly, you can greatly reduce the amount of scrap lumber and odd-size pieces needed. Once you have the size of the exterior walls determined, locate the doors and the windows so one side rests against an existing wall stud. This eliminates an additional wall stud and an odd-size wall cavity. It can be difficult to fit wall insulation into odd-size wall cavities, so fewer of them minimizes the number of voids. Follow the same logic for window locations. The widths of doors is fairly standard, but windows can be made to any size. If possible, size the windows to fit between existing wall studs. Heavy, multiple headers may not be needed in non-load-bearing areas, leaving more room for wall insulation. Since you are designing a two-story house, use stacked wall framing. This means the wall, floor and ceiling lumber is all spaced evenly and located directly above one another. This creates a stronger structure than when they are randomly offset so the header is put under bending stress. Two-stud corner designs use less lumber than standard three-stud corners and blocks. With just two studs, there is more room for insulation, and the cavity is uniform so it is much easier to eliminate insulation voids. Older three-stud corners, because they get cold, sometimes become damp and may be a location for mold to start. Instead of using plywood or OSB sheathing, check your codes about using rigid foam board over the entire exterior. With the proper framing design, it should be adequately strong. Another option is placing the foam board over traditional sheathing. Q. We want to determine the proper indoor humidity level during the winter. We are thinking about buying a humidifier (on sale now) but don't know if we need one. Is there a simple way to tell? A. Whether or not you need a humidifier, and the proper setting, depends upon your climate. In very cold climates, people often set the humidity level such that it is just below the point where windows sweat. In warm climates, where there is not a great indoor-to-outdoor temperature difference, you likely will not need one. Your doctor can recommend the best humidity level based upon allergies, respiratory or other health conditions. Send inquiries to James Dulley, South Bend Tribune, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.dulley.com.